The present invention relates to a method and apparatus for feeding or advancing grid stock material and finds adaptation in the battery grid industry and, in particular, relates to the feeding of workstock to provide cut out portions therein whereby the feeding provide equal slot placement and progression of the workstock.
The subject invention specifically is addressed to methods and apparatus for feeding grid structures having open networks therein whereby the structures are oriented and dimensioned to a predetermined size. Such grid structures are generally made by expanding a metal workstock to form an open network structure and thereafter applying paste thereto by means readily available in the art.
Conventional stock strip feeding devices associated with machine tools including punch presses generally feed stock strip ahead at uniform speeds and the starting and stopping of the feeding movements may oftentimes be so sudden that additional mechanisms are required to insure correct progression. It is generally found that the feeding mechanism is positively actuated, the results being that anything interferring with the advance movement of the stock strip may and frequently will damage the feeding mechanism to say nothing of the stock itself being fed therethrough.
In the feeding mechanism to be described herein the stock strip is not pushed forward to the punch and die means but is drawn rearward or away from said means after an initial punching has been produced. This is important especially when the stock strip is a thin sheet metal such as encountered with lead or lead alloys which would readily buckle under a forward pushing action. Thus, the feeding mechanism herein described relates to advancing relatively soft metals in stock strip form. Moreover, this invention relates to an arrangement that utilizes the openings or slots cut in the stock material itself as an element in determining the accurate feed movement and progression of said stock material.
The step of expansion in the process to form an expanded stock structure may be readily made by conventional processes, such as disclosed in U.S. Pat. No. 3,891,459. After expansion, the expanded structure is subjected to a cutting operation wherein spaced-apart slots are cut from a central unexpanded portion thereof. In accordance with this invention the stock material is advanced into and out of the cutting facility by the feeding mechanism herein described. The process and feeding device for carrying out the invention will be described in more detail hereinafter. Following the cutting step the expanded structure is pasted, the pasting operation being accomplished by moving the structure into a zone where an active material, generally a thick, lead-containing paste, is applied to the open grid network. Various means may be used to apply the active material to the network of the expanded structure.
Briefly, in accordance with this invention, a process and machine is described for feeding battery grid stock through a cutting machine to cut out a group of at least two spaced-apart slots therein, the feeding mechanism comprising supporting means associated with the cutting machine to support the stock during its advance, a pair of members slidably mounted to the supporting means to operate on adjacent groups of spaced-apart slots in the stock, and means timed in respect to said cutting machine and operating to impart feeding movements to said pair of members and hence to said stock.
The aforementioned features with the objects and advantages which become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.